scholarly journals STEADY-STATE MODELLING OF PEM FUEL CELLS USING GRADIENT-BASED OPTIMIZER

10.6036/10099 ◽  
2021 ◽  
Vol DYNA-ACELERADO (0) ◽  
pp. [ 8 pp.]-[ 8 pp.]
Author(s):  
SALAH KAMAL ◽  
ATTIA EL-FERGANY ◽  
EHAB EHAB ELSAYED ELATTAR ◽  
AHMED AGWA

The accuracy of fuel cell (FC) models is important for the further numerical simulations and analysis at several conditions. The electrical (I-V) characteristic of the polymer exchange membrane fuel cells (PEMFCs) has high degree of nonlinearity comprising uncertain seven parameters as they aren’t given in fabricator's datasheets. These seven parameters need to be obtained to have the PEMFC model in order. This research addresses an up-to-date application of the gradient-based optimizer (GBO) to generate the best estimated values of such uncertain parameters. The estimation of these uncertain parameters is adapted as optimization problem having a cost function (CF) subjects to set of self-constrained limits. Three test cases of widely used PEMFCs units; namely, SR-12, 250-W module and NedStack PS6 to appraise the performance of the GBO are demonstrated and analyzed. The best values of the CF are 0.000142, 0.33598, and 2.10025 V2 for SR-12, 250-W module and NedStack PS6; respectively. Furthermore, the assessment of the GBO-based model is made by comparing its obtained results with the experiential results of these typical PEMFCs plus comparisons to other methods. At a due stage, many scenarios as a result of operating variations in regard to inlet regulation pressures and unit temperatures are performed. The copped reported results of the studied scenarios indicate the effectiveness of the GBO in establishing an accurate PEMFC model.

Author(s):  
Scott A. Kenner ◽  
Nicholas M. Josefik ◽  
Scott M. Lux ◽  
James L. Knight ◽  
Melissa K. White ◽  
...  

Background: The U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) continues to manage The Department of Defense (DoD) Residential Proton Exchange Membrane (PEM) Fuel Cell Demonstration Project. This project was funded by the United States Congress for fiscal years 2001 through 2004. A fleet of 91 residential-scale PEM fuel cells, ranging in size from 1 to 5 kW, has been demonstrated at various U.S. DoD facilities around the world. Approach: The performance of the fuel cells has been monitored over a 12-month field demonstration period. A detailed analysis has been performed cataloging the component failures, investigating the mean time of the failures, and the mean time between failures. A discussion of the lifespan and failure modes of selected fuel cell components, based on component type, age, and usage will be provided. This analysis also addresses fuel cell stack life for both primary and back-up power systems. Several fuels were used throughout the demonstration, including natural gas, propane, and hydrogen. A distinction will be made on any variances in performance based on the input fuel stock. Summary: This analysis will provide an overview of the ERDC-CERL PEM demonstration fuel cell applications and the corresponding data from the field demonstrations. Special emphasis will be placed on the components, fuel cell stack life, and input fuel characteristics of the systems demonstrated.


2004 ◽  
Vol 19 (6) ◽  
pp. 1723-1729 ◽  
Author(s):  
Neil Aukland ◽  
Abdellah Boudina ◽  
David S. Eddy ◽  
Joseph V. Mantese ◽  
Margarita P. Thompson ◽  
...  

During the operation of proton exchange membrane (PEM) fuel cells, a high-resistance oxide is often formed on the cathode surface of base metal bipolar plates. Over time, this corrosion mechanism leads to a drop in fuel cell efficiency and potentially to complete failure. To address this problem, we have developed alloys capable of forming oxides that are both conductive and chemically stable under PEM fuel cell operating conditions. Five alloys of titanium with tantalum or niobium were investigated. The oxides were formed on the alloys by cyclic voltammetry in solutions mimicking the cathode- and anode-side environment of a PEM fuel cell. The oxides of all tested alloys had lower surface resistance than the oxide of pure titanium. We also investigated the chemical durability of Ti–Nb and Ti–Ta alloys in more concentrated solutions beyond those typically found in PEM fuel cells. The oxide films formed on Ti–Nb and Ti–Ta alloys remained conductive and chemically stable in these concentrated solutions. The stability of the oxide films was evaluated; Ti alloys having 3% Ta and Nb were identified as potential candidates for bipolar plate materials.


2018 ◽  
Vol 388 ◽  
pp. 350-360 ◽  
Author(s):  
Chang Jie Li ◽  
Ye Liu ◽  
Zhe Shu Ma

An irreversible model of proton exchange membrane fuel cells working at steady-state is established, in which the irreversibility resulting from overpotentials, internal currents and leakage currents are taken into account.In this paper, the irreversibility of fuel cell is expounded mainly from electrochemistry. The general performance characteristic curves are generated including output voltage, output power and output efficiency. In addition, the irreversibility of a class of PEMFC is studied by changing the operating conditions (controllable factors) of the fuel cell, including effect of operating temperature, operating pressure and leakage current. The results provide a theoretical basis for both the operation and optimal design of real PEM fuel cells.


2009 ◽  
Vol 23 (03) ◽  
pp. 537-540 ◽  
Author(s):  
JIANG HUI YIN ◽  
JUN CAO

A general proton exchange membrane fuel cell model including two finite-thickness catalysts is developed in this study, allowing for an in-depth understanding of the effects of the two key electrochemical reactions taking place in the two catalysts. The model is used to predict the performances of fuel cells employing two different flow channel designs, providing insights for fuel cell design and performance optimization.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1884 ◽  
Author(s):  
Ahmed M. Agwa ◽  
Attia A. El-Fergany ◽  
Gamal M. Sarhan

In simulation studies, the precision of fuel cell models has a vital role in the quality of results. Unfortunately, due to the shortage of manufacturer data given in the datasheets, several unknown parameters should be defined to establish the fuel cell model for further precise analysis. This research addresses a novel application of the atom search optimization (ASO) algorithm to generate these unknown parameters of the fuel cell model and in particular of the polymer exchange membrane (PEM) type. The objective of this study is to establish an accurate model of the PEM fuel cells, which will provide accurate results of modeling and simulation in a steady-state condition. Simulations and further demonstrations were performed under MATLAB/SIMULINK. The viability of the proposed models was appraised by comparing its simulation results with the experimental results of number of commercial PEM fuel cells. In the same context, the obtained numerical results by the proposed ASO-based method were compared to other challenging optimization methods-based results. Finally, parametric tests were made which indicated the robustness of the ASO results as well. It can be stated here that ASO performs well and has a good capability to extract the unknown parameters with lesser errors.


Author(s):  
Robert Radu ◽  
Nicola Zuliani ◽  
Rodolfo Taccani

Proton exchange membrane (PEM) fuel cells based on polybenzimidazole (PBI) polymers and phosphoric acid can be operated at temperature between 120 °C and 180 °C. Reactant humidification is not required and CO content up to 1% in the fuel can be tolerated, only marginally affecting performance. This is what makes high-temperature PEM (HTPEM) fuel cells very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. From an experimental point of view, the major research effort up to now was dedicated to the development and study of high-temperature membranes, especially to development of acid-doped PBI type membranes. Some studies were dedicated to the experimental analysis of single cells and only very few to the development and characterization of high-temperature stacks. This work aims to provide more experimental data regarding high-temperature fuel cell stacks, operated with hydrogen but also with different types of reformates. The main design features and the performance curves obtained with a three-cell air-cooled stack are presented. The stack was tested on a broad temperature range, between 120 and 180 °C, with pure hydrogen and gas mixtures containing up to 2% of CO, simulating the output of a typical methanol reformer. With pure hydrogen, at 180 °C, the considered stack is able to deliver electrical power of 31 W at 1.8 V. With a mixture containing 2% of carbon monoxide, in the same conditions, the performance drops to 24 W. The tests demonstrated that the performance loss caused by operation with reformates, can be partially compensated by a higher stack temperature.


2021 ◽  
Vol 11 (5) ◽  
pp. 2052
Author(s):  
Amlak Abaza ◽  
Ragab A. El-Sehiemy ◽  
Karar Mahmoud ◽  
Matti Lehtonen ◽  
Mohamed M. F. Darwish

In recent years, the penetration of fuel cells in distribution systems is significantly increased worldwide. The fuel cell is considered an electrochemical energy conversion component. It has the ability to convert chemical to electrical energies as well as heat. The proton exchange membrane (PEM) fuel cell uses hydrogen and oxygen as fuel. It is a low-temperature type that uses a noble metal catalyst, such as platinum, at reaction sites. The optimal modeling of PEM fuel cells improves the cell performance in different applications of the smart microgrid. Extracting the optimal parameters of the model can be achieved using an efficient optimization technique. In this line, this paper proposes a novel swarm-based algorithm called coyote optimization algorithm (COA) for finding the optimal parameter of PEM fuel cell as well as PEM stack. The sum of square deviation between measured voltages and the optimal estimated voltages obtained from the COA algorithm is minimized. Two practical PEM fuel cells including 250 W stack and Ned Stack PS6 are modeled to validate the capability of the proposed algorithm under different operating conditions. The effectiveness of the proposed COA is demonstrated through the comparison with four optimizers considering the same conditions. The final estimated results and statistical analysis show a significant accuracy of the proposed method. These results emphasize the ability of COA to estimate the parameters of the PEM fuel cell model more precisely.


2016 ◽  
Vol 839 ◽  
pp. 165-169 ◽  
Author(s):  
Thomas Luschtinetz ◽  
Andreas Sklarow ◽  
Johannes Gulden

Liquid organic hydrogen carriers (LOHC) are a promising form to store hydrogen. However, the process of dehydrogenation has to be demonstrated for applications with proton exchange membrane (PEM) fuel cells which require very pure hydrogen. Here we document the measured degradation effects due to CO contamination on a PEM fuel cell that is supplied with hydrogen from a LOHC and we want to use later in a maritime application.


Author(s):  
Sreedhar Kari ◽  
George Thorne ◽  
John Szeki ◽  
Chris Hall ◽  
Lindsey Mortimer ◽  
...  

Abstract Increased greenhouse gas emissions have an adverse impact on climate change. Recently, there is an increased drive to reduce the emissions especially after the Paris agreement 2015. There are several research initiatives that have been started in the aerospace industry to reduce the emissions like NOx, CO2 and other harmful substances. This paper presents the case studies done on the potential applications of fuel cells for more electric aircrafts (MEA) to achieve the reduced emissions and reduced fuel consumption. The objective of this paper is to take a broad view of how fuel cell technology works, various types of existing technologies and their potential applications and challenges for aero engines in terms of power density. In this study, the different types of fuel cells e.g. low temperature Proton Exchange Membrane (PEM) fuel cells and high temperature solid oxide fuel cells (SOFC) etc were studied and identified the opportunities and challenges to make them work for aero engines as a part of electrification. Different ways of storing the hydrogen on board have been explored. The comparison has been made with battery vs fuel cell power density including the H2 tank. The case studies were made for potential replacement of shaft power off take on civil large engines with fuel cells for hybrid long range aircrafts and regional propeller jets with fully electric power.


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